A side structure disclosed in Patent Literature 1 is known as a side structure of a vehicle body that appropriately controls the deformation of the vehicle body when a collision occurs from the side surface of a vehicle. In the structure disclosed in this literature, basically, an outer end of a room partition panel is joined to a side member inner; a striker retainer is joined to a side member outer; and a rear member, which is laid inside in the vehicle width direction by a cross member, is connected to the rear portion of a B pillar. According to this structure, a collision load generated at the time of a lateral collision is transmitted from the striker retainer to the room partition, the rear member, or the cross member through the forward wall of the side member outer or that of the side member inner. Accordingly, internal deformation in the vehicle width direction is suppressed.